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perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()

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Dan Carpenter pointed out that the control flow in pt_pmu_hw_init()
is a bit messy: for example the kfree(de_attrs) is entirely
superfluous.

Another problem is the inconsistent mixing of label based and
direct return error handling.

Add modern, label based error handling instead and clean up the code
a bit as well.

Note that we'll still do a kfree(NULL) in the normal case - this does
not matter as this is an init path and kfree() returns early if it
sees a NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150409090805.GG17605@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2015-04-12 11:11:21 +02:00
parent 5dafd7cb96
commit 066450be41
1 changed files with 30 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
arch/x86/kernel/cpu/perf_event_intel_pt.c
View File

@ -119,48 +119,55 @@ static int __init pt_pmu_hw_init(void)
struct dev_ext_attribute *de_attrs;
struct attribute **attrs;
size_t size;
int ret;
long i;
if (test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT)) {
for (i = 0; i < PT_CPUID_LEAVES; i++)
cpuid_count(20, i,
&pt_pmu.caps[CR_EAX + i * 4],
&pt_pmu.caps[CR_EBX + i * 4],
&pt_pmu.caps[CR_ECX + i * 4],
&pt_pmu.caps[CR_EDX + i * 4]);
} else {
return -ENODEV;
attrs = NULL;
ret = -ENODEV;
if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT))
goto fail;
for (i = 0; i < PT_CPUID_LEAVES; i++) {
cpuid_count(20, i,
&pt_pmu.caps[CR_EAX + i*4],
&pt_pmu.caps[CR_EBX + i*4],
&pt_pmu.caps[CR_ECX + i*4],
&pt_pmu.caps[CR_EDX + i*4]);
}
size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps) + 1);
ret = -ENOMEM;
size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps)+1);
attrs = kzalloc(size, GFP_KERNEL);
if (!attrs)
goto err_attrs;
goto fail;
size = sizeof(struct dev_ext_attribute) * (ARRAY_SIZE(pt_caps) + 1);
size = sizeof(struct dev_ext_attribute) * (ARRAY_SIZE(pt_caps)+1);
de_attrs = kzalloc(size, GFP_KERNEL);
if (!de_attrs)
goto err_de_attrs;
goto fail;
for (i = 0; i < ARRAY_SIZE(pt_caps); i++) {
de_attrs[i].attr.attr.name = pt_caps[i].name;
struct dev_ext_attribute *de_attr = de_attrs + i;
sysfs_attr_init(&de_attrs[i].attr.attr);
de_attrs[i].attr.attr.mode = S_IRUGO;
de_attrs[i].attr.show = pt_cap_show;
de_attrs[i].var = (void *)i;
attrs[i] = &de_attrs[i].attr.attr;
de_attr->attr.attr.name = pt_caps[i].name;
sysfs_attr_init(&de_attrs->attr.attr);
de_attr->attr.attr.mode = S_IRUGO;
de_attr->attr.show = pt_cap_show;
de_attr->var = (void *)i;
attrs[i] = &de_attr->attr.attr;
}
pt_cap_group.attrs = attrs;
return 0;
err_de_attrs:
kfree(de_attrs);
err_attrs:
fail:
kfree(attrs);
return -ENOMEM;
return ret;
}
#define PT_CONFIG_MASK (RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC)